EXPERIMENTS IN HYBRIDISATION, &c. ti? 
same seed-capsule, no two are alike, and yet all show distinct traces of 
their ancestry, and well illustrate the law of Partial Prepotency. 
One point may be noted here that comes out clearly in an examina- 
tion of the above hybrids, and that is the latency of certain characters 
in the first generation which come out markedly in the second generation. 
The hybrid parent of these twenty-four hybrids, P. x politum, fails 
to show the colour characters of one of its own parents, P. barbatum, in 
the leaves ; yet in a number of cases these same colour characters re- 
appear strongly in the second generation, clearly showing that certain 
characters may remain latent in one generation to reappear in the next. 
THe Fertiniry oF Hyprips. 
The question of the fertility of hybrids is very important both to the 
student and to the practical breeder. Ifahybrid, 7.e. a first cross between 
two distinct species, be not fertile, its further improvement by crossing 
is obviously barred; but if it prove fertile in however small a degree, 
then in the hands of the skilled hybridist it may prove to be the starting- 
point of a series of variations of great economic value. 
Amid the many misconceptions concerning hybrids in the popular 
mind perhaps none has clung so tenaciously as the belief in their absolute 
infertility. In studying the records of our foremost hybridists—Kolreiiter, 
Gartner, Herbert, Darwin, Kerner, Naudin, and Dr. Focke—one is im- 
pressed at once with the undoubted fertility of many hybrids, and I 
have compiled a list of genera from these authorities, and from my own 
observations, in which fertile hybrids are known. I find that no less 
than ninety distinct genera are recorded in which fertile hybrids are 
known, and only four in which the hybrids are all quite infertile. 
This list is doubtless incomplete, yet it may possibly serve a useful 
purpose in demonstrating the undoubted fertility of many hybrids, and 
the rare absolute infertility of others, 
In the natural order Composite we have fertile hybrids in Cirsium, 
Inula, Chrysanthemum, Senecio, Hieracium, Lactuca, and Tragopogon. 
In Rosacez we have Prunus, Pyrus, Fragaria, Geum, Rosa, Rubus, 
and Cratzgus. 
In Ranunculacez : Anemone, Aquilegia, and Clematis. 
In Gesneraceze : Achimenes, Streptocarpus, Isoloma, and Gloxinia. 
In Carophyllez : Silene, Lychnis, Melandrium, and Dianthus. 
In Lilacew: Scilla, Chionodoxa, and Chionoscilla. 
in Solanacex : Solanum, Datura, Nicotiana, and Petunia. 
In Scrophularinee : Calceolaria, Veronica, Verbascum, and Linaria. 
In Amaryllidee : Hippeastrum, Crinum, Narcissus. 
In Campanulacee : Campanula and Lobelia. 
In Geraniacez : Pelargonium and Ciconium. 
In Ericacew : Rhododendron and Erica. 
In Cucurbitacez : Cucumis and Cucurbita. 
In Onagrariee : @nothera and Epilobium. 
In Graminee : Triticum and Aigilops. 
In Leguminose : Cytisus, Medicago, Pisum, and Phaseolus. 
In Malvacee: Abutilon and Lavatera. 
In Orchidew : Paphiopedilum, Phragmipedilum, Calanthe, Cattleya, 
